Extrusion presses



March 30, 1965 H, H ROOS Em 3,175,384

EXTRUSION PRESSES Filed July 23, 1962 3 Sheets-Sheet 1 March 30, 1965 H. H. GROOS ETAL 3,175,384

EXTRUSION PRESSES Filed July 25, 1962 3 Sheets-Sheet 2 March 30, 1965 H. H. GROOS ET AL EXTRUS ION PRES SES 3 Sheets-Sheet 3 Filed July 23, 1962 United States Patent 3,175,384 EXTRUSION PREES Horst Hans Groos and Karl Linders, Dusseldorf, Germany, assignors to Schloeman Alrtiengesellschaft, Dusseldorf, Germany Filed July 23, 1962, Ser. No. 211,676 Claims priority, application Germany, Aug. 5, 1961, Sch. 30,096 8 Claims. (Cl. 72--255) This invention relates to an extrusion press, and more particularly to a four-column horizontal press, with an axially displaceable container, and with a die-holder that can be moved radially in and out upon a frame between the container and a bolster. With the frame hitherto known for the die-holder, the die has to be taken out of the frame on the side opposite to the axis of the press, and replaced by a fresh one, which is then, upon the frame, run in to the axis of the press.

In order to facilitate the changing of the die, in the case of another design a double rotary arm has been employed, which is rotatable or rockable about an axis parallel to the axis of the die, and which can accommodate a die at each end. After the termination of an ex trusion operation the container is run back, and the rotary arm is rocked through about 180, so that the die with which the last extrusion has been effected is rocked out of the axis of the press. The die mounted at the other end of the rotary arm is thus swung into the press axis during the rocking of the rotary arm, as in patent application No. 39,165, filed June 27, 1960, issued as Patent No. 3,119,493. The rapid method of working hereby attained is however, in the known constructions, positively associated with a substantially greater expenditure on construction. Whereas normally the column spacing, of three or four columns for example, is only of such dimensions as are required by the diameter of the container, it has now been necessary to select a greater distance between columns, in order to obtain the space necessary for rocking the rotary arm. Any increase in the spacing of the columns gives rise to greater bending moments in the bolster and in the press cross-bar, and also in the press cross-head, so that the increase in the size of the last-mentioned members, necessary owing to the increase in the distance between the columns, involves a considerable increase in the structural weights.

In order to obviate this disadvantage, according to German Patent No. 1,118,130, a frame with two guides one above the other has been provided for two die-holders running one above the other. This previously unknown construction, however, on account of the two superposed guideways, needs a very lofty guiding frame, and this has a disturbing effect.

The object of the present invention is to obviate the disadvantages of the constructions mentioned, while combining their advantages, and enabling the insertion and removal of the dies always to be efiected on the same side of the press.

The invention attains this aim by virtue of the feature that the frame upon which the die-holder can be run radially in and out is rockable about an axis parallel to the axis of the press, the die-holder not needing to be run out beyond the axis of oscillation of the frame. If a die-holder is provided at each end of a double-armed frame, the two die-holders travel inwards towards the axis of turning, from their positions at the ends of the frame, as a result of which the distance between them diminishes, so that the frame can be rocked even when the columns of the press are comparatively near together.

In order to simplify the displacement movement of the die-holders upon the frame and the turning of the frame about its axis, it is materially helpful if the die-holder, which is slidable upon the frame, has a toothed rack, with which there meshes a pinion coaxial with the axis about which the frame turns, this pinion being rotatable independently of the frame. The rotary driving of the frame, and the sliding movement of the die-holder upon the frame, can then be eifected by means of eo-axial control shafts.

In order to enable the die to be accurately centered in the axis of the press, the position of the die upon the frame is determined by means of an adjustable stop, and the drive for the die is yieldingly constructed so that the die-holder can be run up against the said stop. This is preferably eitected in such a way that the driving of the pinion is effected not in a positive manner, but in a yielding manner, by hydraulic means for example.

If the stop, which, like the die-holder, overlaps the die with a ledge, and thereby holds it during the withdrawal of the container, is so constructed that it can travel radially outwards until the ledge sets the die free, the die, after the die-holder and the stop have travelled radially outwards, can be carried along by the returning container, so that a severing of the product behind the die is thereupon possible by means of a saw. This is particularly desirable when so-called bridge dies are employed.

In order to keep the frame as free as possible from the pulling action of the receding container, guiding bodies are provided on the bolster, and behind these there passes a part of the die-holder which extends out of the frame as the die-holder travels outwards.

The travelling of the die-holder outwards from the press axis requires a very great force if by this outward travel the product is to be severed, in a manner known in itself, between a thrust collar and a stationary cutting edge. In order to provide this force in the most advantageous manner possible, there is mounted on the bolster an appliance for displacing the die-holder, together with tools, towards the axis about which the frame turns, which, preferably through an aperture in the die-holder, acts directly upon a thrust collar which is constructed for shearing the product in co-operation with a shearing edge fixed to the bolster.

One constructional example of the invention is illustrated by the accompanying drawings, in which:

FIGURE 1 shows a cross section through a press on the line 1-1 in FIGURE 2;

FIGURE 2 a section on the line 11-11 in FIGURE 1; and

FIGURE 3 a section on the line 11l111 in FIG- URE 1.

The bolster 1 of the press is connected by four tie-rods 2 with the cylinder, not shown, of the press ram. In the bolster 1 are provided two cylinders 4, one above and one below the axis of the press. In these cylinders slide pistons, the piston rods 3 of which are each secured to a cross-bar 5. Rods 6 secured to the cross-bars 5 are attached to a container '7, which, upon pressure fluid being admitted to the cylinders 4, is displaced by means of the piston rods 3, the cross-bars 5 and the rods 6. The container 7 slides upon tracks 8, and bears, in the position shown in FIGURE 2, upon the die 9, which in its turn is supported, by way of thrust collars 1i and 11 and a pressure piece 12, against the bolster 1. The die 9, together with the thrust collars and 11, is seated in a die-holder 13 which, in FIGURE 1, is open towards the right. The die-holder 13 is rigidly connected with a toothed rack 14, which meshes with a pinion 15, which is mounted upon a hollow shaft 16. This hollow shaft is journalled in a bush or sleeve 17, and carries at its other end a pinion 18, which meshes in its turn with a further pinion 20. This pinion is engaged by a toothed rack 21, which can be moved up and down by means of a piston, not shown, which slides in a cylinder 22. As the rack 21 moves up and down, therefore, the die-holder 13 slides upon lower and upper guideways 23 and 25, located in a frame 24, which in its turn is carried by the sleeve 17, or may be integral with this sleeve, as shown in FIGURE 3.

The frame 24, with the guideways 23 and 25, is rigidly connected, by way of a cover plate 26, with a solid shaft 27, which is rotatable in the hollow shaft 16, and carries, at its rear end, a pinion 28, which meshes with a pinion 29, which in its turn is rotated by a toothed rack 30, when the latter is moved upwards or downwards by a piston, which can slide in a cylinder 31. By moving the piston in the cylinder 31, therefore, the shaft 27 is rotated, together with the cover plate 26, the frame 24, and the guideways 23 and 25. The hollow shaft 16 can be moved independently of this by actuating the rack 21.

The die-holder 13 is in FIGURE 1 moved so far out of the frame 24 towards the right that the die 9 carried by it bears against a stop 32, which is displaceably arranged on the bolster 1, and which overlaps the die 9 with a ledge 32a. The stop 32 can be adjusted by turning an abutment screw 33. This adjustment is effected in such a way that the die 9 is located in the press axis when the die-holder has come up against the stop 32. The dieholder 13 is moreover held above and below by holding bodies 34 and 34a respectively, which are each secured to the bolster 1 by an anchoring bolt 35. Then the dieholder 13 is moved towards the left (in FIGURE 1,) it becomes free from the holding bodies 34 and 34a. In the position illustrated, however, the holding bodies 34 and 34a support the die-holder 13 against any pull in the axial direction, that is, towards the right of FIGURE 2. Such an axial pull occurs for instance when the container 7 is being withdrawn from the die 9.

A second die-holder 39, with a second die 33, is displaceable between the same tracks as the die-holder 13. Its toothed rack 39a meshes from below with the pinion 15, so that by admitting pressure fluid to the cylinder 22, and thereby rotating the pinions 20, 18 and 15, the dies 9 and 38 are simultaneously drawn inwards towards the shaft 27 or moved away from it. When the two dies have been drawn inwards, the shaft 27, together with the cover plate 26 and the frame 24, can be rotated, the dies and the die-holders no longer protruding from the ends of the frame, and not extending beyond the circle 40, which indicates that the columns 2 do not stand in the way of the rotation of the frame 24.

Upon the bolster 1 there is furthermore arranged a casing 41 enclosing an ordinary product-shearing means, the blade 42 of which can be lowered downwards until it passes close by the die 9, for the purpose of cutting off a length, which lies free after retraction of the container 7, in front of the die, that is, in FIGURE 2, to the right of the die.

Upon the thrust collar 11 there can act a movable cylinder 44, in which is mounted a piston, which, with its piston head 45, is stationarily attached in any way to the bolster 1. When the cylinder 44 receives hydraulic pressure, it presses against the thrust collar 11. When a length of product 46 is extending through the thrust .collar 11, this product would prevent the die-holder 13 4 being drawn in towards the axis of the shaft 27 by rotation of the pinions 2t), 18 and 15. The pressure of the cylinder 44 is however suflicient to move the thrust collar 11 out of alinement with the stationary pressure body 12, thereby shearing the product, since the pressure body 12 and the thrust collar 11 are provided with corresponding shearing edges for this purpose. The shearing of the product by means of the cylinder 44 is effected more particularly when instead of the die 9 a bridge die is put in, which projects far into the die-holder 13, so that a shearing of the product by means of the shears 41, 42 is not possible.

The arrangement of tools illustrated furthermore enables the product to be sheared behind the die, this being by virtue of the fact that the die-holder 13 is drawn away towards the left (in FIGURE 3) of the die 9, and at the same time the stop 32 is displaced towards the right by shifting the abutment screw 33. It is then possible to draw back the container, together with the extrusion residue and the die, as well as the extruded product, so that the position 9a of the die represented in FIGURE 3 is reached. During this operation the die-holder 13 is held fast by the holding bodies 34 and 34a. When the die has reached the position 9a, cutting can be effected in the direction of the arrow 48 by means of a saw.

We claim:

1. An extrusion press, comprising: a bolster, a container displaceable axially towards and away from the bolster, a shaft rotatable in the bolster about an axis parallel to the axis of the press, a frame rigidly connected with the said shaft, so as to be rockable about the axis of the shaft, guideways in the frame, and a die-holder, with a die, slidable in the guideways between an operative position co-axial with the press, in which it protrudes from the end of the frame, and an inoperative position nearer to the axis of the rotatable shaft.

2. An extrusion press as claimed in claim 1, the frame, with its guideways, extending on both sides of the shaft, and the press comprising two die-holders, both slidable in the guideways of the same frame, on opposite sides of the axis of the shaft.

3. An extrusion press as claimed in claim 1, the guide ways being on opposite sides of the axis of the rotatable shaft and equidistant therefrom, so that when the dieholder is in its operative position the guideways are equi distant from a plane containing the axis of the press and the axis of the rotatable shaft.

4. An extrusion press as claimed in claim 1, further comprising: a toothed rack secured to the die-holder and parallel to the guideways, and a pinion, coaxial with the rotatable shaft but rotatable independently of this shaft and of the frame, the said pinion meshing with the said rack.

5. An extrusion press as claimed in claim 4, further comprising: means for rotating the said pinion, the said means being of a yielding nature, hydraulic means for example, and an adjustable abutment located on the bolster for stopping the outward sliding motion of the dieholder when it reaches its operative position.

6. An extrusion press as claimed in claim 5, further comprising a ledge on the adjustable abutment adapted to overlap the die when in the operative position, and to hold the die against retraction when the container is being moved away from the bolster, the abutment being withdrawable to liberate the die when required.

7. An extrusion press as claimed in claim 1, further comprising holding bodies, mounted on the bolster, adapted to engage the portion of the die-holder that protrudes from the frame when in the operative position, and to hold it against an axial pull.

8. An extrusion press as claimed in claim 1, further comprising: a thrust collar on the die-holder, a stationary pressure piece co-axial with the press, co-operating shearing edges on the thrust collar and the stationary pressure piece, means acting directly upon the thrust collar for 5 t3 forcing the die-holder transversely out of its operative 2,858,017 10/58 Kent et a1. 2071.1 position towards the axis of the rotatable shaft When an 2,896,782 7/59 Billen 2071.1 extrusion product is extending through the pressure piece, 2,914,171 11/59 Hofimann 207--1.1 the thrust collar and the die, and thereby shearing the 2,963,151 12/60 Kent et a1. 207-1.1 extruded product. 5 3,019,894 2/ 62 Delcroix et al. 207--1.1

References Cited by the Examiner FOREIGN PATENTS UNITED STATES PATENTS 1261559 4/61 France- 2,720,9'70 10/55 Roux 207-1.1 MICHAEL V. BRINDISI, Primary Examiner. 2,768,406 10/56 Carle 207-11 10 WILLIAM W. DYER, JR., Examiner. 

1. AN EXTRUSION PRESS, COMPRISING: A BOLSTER, A CONTAINER DISPLACEABLE AXIALLY TOWARDS AND AWAY FROM THE BOLSTER, A SHAFT ROTATABLE IN THE BOLSTER ABOUT AN AXIS PARALLEL TO THE AXIS OF THE PRESS, A FRAME RIGIDLY CONNECTED WITH THE SAID SHAFT, SO AS TO BE ROCKABLE ABOUT THE AXIS OF THE SHAFT, GUIDEWAYS IN THE FRAME, AND A DIE-HOLDER, WITH A DIE, SLIDABLE IN THE GUIDEWAYS BETWEEN AN OPERATIVE POSITION CO-AXIAL WITH THE PRESS, IN WHICH IT PROTRUDES FROM THE END OF THE FRAME, AND AN INOPERATIVE POSITION NEARER TO THE AXIS OF THE ROTATABLE SHAFT. 